How to make the assembler pre process the .S file before assembling under Keil MDK?

How to make the assembler pre process the .S file before assembling under Keil MDK?

With other tools , assembler auto pre process the .S , but Keil MDK does not.

how to set?

code like :

#define ENTRY(name) /
  .globl name; /
  ALIGN; /
  name:

ENTRY(__udivsi3)

will warning like this

lib1funcs.S(44): error: junk at end of line, first unrecognized character is `/'
lib1funcs.S(45): error: bad instruction `align'
lib1funcs.S(45): error: junk at end of line, first unrecognized character is `/'
lib1funcs.S(216): error: bad instruction `entry(__udivsi3)'

Tool Version Numbers:
Toolchain: MDK-Lite Version: 4.71.0.0
Toolchain Path: C:\Program Files (x86)\GNU Tools ARM Embedded\4.7 2012q4\bin
C Compiler: GCC.Exe
Assembler: AS.Exe
Linker/Locator: LD.Exe
Librarian: AR.Exe
Hex Converter: OBJCOPY.Exe